Coroplast scale buildings

[Supermario]

The only tricky part is cutting the fold points. Because of the size of building I had to use the 8' length of the sheet, same direction the ribs run to make it all one piece. Could build in sections for larger stuff but I like the solid feel of one continuous piece.
Anyway, this all means the fold cuts are across the grain of the sheet. So I mark the distance I want, then make a mark 5mm on each side of that line.carefully cut through just one layer and then trim each individual rib off. After you cut a few and have something to grab onto its easy going. Pulling up on the scrap piece as you just touch with a knife and it cuts clean off. Trick is to get as close to the outer layer so it will fold easy but not cut through the outer layer.

I didn't take the time to cut close in these pics And the fold is a little stubborn till I trimmed. Smaller buildings none of this is an issue as following the ribs makes life easy like the stairs were to make.